Venetian blind



F. GRIESSER VENETIAN BLIND Feb. 8, 1955 2 Shee'ts-Sheet 1 Filed Sept. 22, 1952 Feb. 8, 1955 F. GRIESSER 2,7o1,611

VENETIAN BLIND i Filed Sepfc. 22, 1952 2 Sheets-Sheet 2 IN V EN TOR. G/v'c': S l' VENETIAN BLIND Fritz Griesser, Aadorf, Switzerland, assignor to Rolladenfabrik A. Griesser. A.-G., Aadorf, Switzerland Application'September 22, 1952,2Serial No. 310,852

Claimsl priority, application Switzerland SeptemberA 27, 1951 1 Claimi.. (Cl. 160-170) This invention relates tol Venetian blinds of the type in which the slats are carried by ladder tapes suspended from tilt members which are mounted for tilting movement onv the blind lifting shaft, While the blind lifting element attached to the lowermost slat winds up on a spool fixed to the shaft.

It is an object of the invention to provide means for tilting the slats by actuation of the blind lifting member without requiring a special* actuating member for the tilting operation.

According to the invention.V the blind lifting shaft is connected by means of 'a' friction clutch with the tilt members mounted on thetshaft to enable tilting ofi the slats in any positiontof the blind.

Further objects and advantages: will appear from the following description' of preferred embodiments of the invention as illustrated in theaccompanying drawings:

Fig. 1` is a Vertical longitudinal. section through the casing in which the lifting and tilting mechanism is ar'- ranged;

Fig. 2 is afragmentary' section showing a portionv of Fig. 1 drawn to a larger scale;

Figs. 3, 4 and 5 are each a transversesection along' the line A-A of' Fig. 2 showing the members in different positions of operation;

Fig. 6 is a section along the line B-B`of Fig. 2;

Fig. 7 shows a detail of' Fig. 6 in longitudinal section;

Fig, 8' is a fragmentary longitudinal section through a modified lifting and tiltingv mechanism of the blind;

Fig. 9 is a transverse section along the line IX-IX of- Fig; 8;

Fig. 104 is a transverse section along the line X-X of Fig. 8;

Fig. ll is a longitudinal section showing a modified clutch mechanism;

Fig. 12 is a transverse section along the line'XII-XII of' Fig.v 11.

As represented' in Figs; 1 to' 6, the' blind lifting and slat tilting mechanismV is mounted' inv an upwardly open casing I, in which a shaft 2 is rotatably carried in bearing brackets 3. The' shaft 2 may be turned by. means of a hand crank (not shown) actuating a bevel gear 4 which isl operatively` connected'to the shaft? 2 by means of a friction clutch 5 as shown intmy` earlier U. S. Patent No. 2,579,144. The friction clutch prevents a rotation of the shaft 2 under the action of the turning moment applied tothe shaftV by the weight! of the slats` 11.

A sleeve `6-isfreely rotatable on the shaft 2l` and has its two endsrigidly connected to arms- 7. Each. arm 7 is connected by means of a cylindrically curved sheet metal piece 8 to a second arm 9 also rotatably mounted on the shaft 2. The ladder tapes 10 are placed over the sheet metal piece 8 and secured thereon against sliding. The sheet metal piece 8 together with the two arms 7 and 9 form a tilt member, and the ladder tape suspended therefrom passes through slots 12 in the bottom of the casing 1. Each of the sheet metal pieces 8 of the two tilt members partly surrounds a winding spool 13 secured to the winding shaft 2. The spool is provided with a circumferential groove 14. The lifting element 15 in the form of a thin flat steel ribbon is fixed to the bottom of the groove and winds up around the spool. The ribbon 15 is guided between two rollers 16 carried by the bottom of the casing 1, and passes through an opening in the bottom (Fig. 6) and through a slot in each slat 11, in order to be attached as is well known, to the bottom slat.

United States Patent O 2,701,61 l Patented Feb. 8,1955

The spool 13 is providedwith a radial holereceiving a coiled spring 17 the outer end of which acts against a pin 18 arranged to slide iniradial slots 19V of the spool flanges. The pin 18 carries two bolts 20 having bevelled outer edges.l When thev steel ribbonv 15 is` wound up aroundthespool andithe pin 18, this latter is maintained at the inner ends of the slots 19 and the bolts 20 are retracted within the spoolfianges. Only when the blind is fully lowered,- the pin 181 is released by the steel' ribbonvwhieh is then= fully unwound. Thelspring 17 then pushes the pin'18'against.thetouter'ends of the slots 19 into the position shown in Fig. 7. The bolts 20* are thus' outwardly projected beyond the periphery of the spool 13.

The arm 9 of' one of the tilt members 7, 8,V 9, carries a pin extending parallel to the shaft 2". On this pin is mounted a forked member 22 surrounding the shaft 2 and' forming. one part' of a friction coupling. The member 22 is internally lined' with friction layers 23, for example of cork, asbestos alloy, rubber, synthetio material, or the like, which layers 23 are applied against the winding shaft 2. The pressure exerted by the friction layers 23v onthe shaft 2fcan' be. adjusted by means of a screw 24 connecting the tworends of the forked member 22. In orderv to'render` the coupling resilient, a spring may be introduced between the screw head and one end of the memberv 22,.and in order to provide a larger friction surface, lthe shaft may have. an increased diameter at the place where it'isfengaged by the friction members, or a collar ofr bigger. diameter. secured to the shaft may be provided withv the'v frictionV surface, asl shown in Figs. 8 to 10. The bearingbracket 3 adjacent to the armv 7 of' the tilt member is provided with'two lateral abutments 25 disposed symmetrically with respectv to the Vertical aXial plane through the. shaft4 2' and projecting into the path of the edges of` the arm 7 so as) to formstops limiting'the swing'ing movement of the tilt member.

Lifting of the blind' is efected byV turning the winding shaft with'thespools 13 in the direction of the arrow a in Fig. 3'. It will be seen that the forked member: 22 ofthe friction'coupling is takenalong'with theshaft and by the intermediary' of the pin 21 carried by the tilt members 7, 8), 9, this latter is swung until the arm 7 abuts against the left hand stop 25 in Fig. 3. Owing to this tilting movement, the ladder tape'portion 10 on one side'of the slats is raisedand on the other side lowered, so that. the slats take thev inclined position shown in Fig. 3. When the-shaft 2.' is further turned in the same direction, the forked member 22 remains in its position with the tilt member applied: against; the stop 25 while the shaft 2" slides' with respect to thel friction layers 23', and'the' blind isV raised. In order to tilt the slats in any intermediaryposition` of'the blind; for example to horif zontal position as shown' in Fig'. 4, the winding. shaft 2 is turned through a small ang-le in= a direction opposite to' the-arrow a. The friction coupling becomes' effective again and. the forked member 22 is4 taken along bythe shaft; further rotation' of' the shaft 2 is stopped'. when the slats 11 have x been brought to the=V desired` horizontal position.

When the blindv istto be loweredthe shaft| 2' is turned in' a direction opposite tothe arrow a. The forked'lmemf ber; 2'2and? the tltf members 7; 8; 9'l are. swung' by the shaftf 2' in the same direct'ion' an'd:A the slatsy tilted' into the position shown in Fig. 5. When the arm 7 abuts against the right hand stop 25 in Fig. 5 the forked member 22 and the tilt member remain in the position, while the shaft 2 continues to rotate and the blind is lowered with the slats in the position shown in Fig. 5, while the lifting ribbon 15 unwinds from the spool 13.

The tilt members 7, S, 9 remain in any position of inclination into which they have been brought intermediate the two end positions shown in Figs. 3 and 5, since the friction coupling 5 associated with the driving gear 4 prevents any undesired rotation of the shaft 2 or lowering of the blind under the infiuence of the weight of the slats.

When the blind is completely lowered the steel ribbon 15 is unwound from the spool 13 and releases the pin 18 which now causes the bolts 20 to slide outwardly by the action of the spring 17. When the shaft 2 is further turned in the direction corresponding to lowering of the blind, the projecting bolts 20 abut against the left hand edge of the Sheet metal piece 8 of the tilt member which itself is maintained against rotation by the right hand stop 25. Accordingly, the shaft 2 caunot bel turned further in the direction corresponding to lowering the blind, thereby preventing that the lifting ribbon will wind up on the spool 13 in the wrong direction, and indicating to the operator that for lifting the blind, the shaft 2 must be turned in the opposite direction.

When the blind is fully lowered, tilting of the slats again is effected by rotation of the shaft 2 in the direction of the arrow a, opposite to the direction of lowering the blind, to produce a swinging movement of the tilt members 7, 8, 9.

When the blind is raised from fully lowered position, the gear 4 is operated to turn the shaft in the direction of the arrow a. The bolts are then pulled inwardly by the lifting ribbon 15 winding up on the spool 13 over the pin 18.

It has been understood, that the described mechanism enables to lift and lower the blind and to tilt the slats in any position of the blind by one single actuating member, the winding shaft 2 only requiring to be turned, for tilting the slats, opposite to the preceding turning movement used to lower or to raise the slats.

When a usual raising rope, chain or barrel Operating a pulley or spool on the winding shaft is provided as shown in Fig. 8, instead of the hand crank and gear 4 of Pig. 1, the locking device constituted by the members 17, 18, 19 and 20 on the spool 13 are not used.

In Fig. 8 one end of the winding shaft 2 is connected to a spool 26 to which an Operating tape, not shown, will be attached. The shaft 2 is carried by bearing brackets 3 in the casing 1. The tilt members 7, 8, 9, one of which only is shown in Fig. 8, are rigidly connected at either side to a sleeve 27 and 28, respectively. These sleeves are freely rotatable on the shaft 2 and in openings provided in the brackets 3. The sleeve 27 has a square portion 29 to which the sleeve 6 is connected for transmitting the tilting motion of the members '7, 8, 9 to the second tilt member mounted on the shaft 2 similarly as shown in Fig. 1. A stop 30 on the tilt member cooperates with two abutments on one of the bearing brackets 3 to limit the swinging movement of the tilt member in both directions of rotation. The sleeve 28 secured to the tilt member comprises a square portion 33 outside of the bearing bracket 3. A collar 34 is fixed to the shaft to turn therewith adjacent to the square portion 33 of. the sleeve 28. A sheet metal member 35 is fixed to the square portion 33 by having cut therefrom two arms 36 and connected their ends by a screw 37. Two further arms 38 are cut from the same sheet metal member and passed around the collar 34. These latter arms are lined with a braking layer 39 surrounding the periphery of the collar 34. The ends of the two arms 38 are connected by a screw 40 screwing into one of the arms while clamping pressure is applied to the other arm by means of a spring 41 inserted between this other arm and the screw head 42. In this manner, the friction pressure exerted by the braking layers 39 of the arms 38 may be yieldingly adjusted.

Operation of this example is the same as that described with reference to Figs. 1 to 5. The shaft 2 is turned in one or the other direction when turning the spool 26 by means of the Operating tape. The collar 34 turns with the shaft 2 and by the intermediary of the friction or sliding clutch formed by the collar and the two brake arms 38 rotation of the shaft 2 is transmitted by the sleeve 33, 28 to the tilt members 7, 8, 9. Accordingly the tilt member turns with the shaft 2 through a limited angle until its stop 30 abuts against the abutment 31 or 32, and then the shaft 2 slides relatively to the braking layers 39. In this manner it is possible, by operation of the pull tape carried by the spool 26, to tilt the slats in any position of the blind.

The example according to Figs. 11 and 12 is similar to that just described. I-Iowever, the friction or sliding clutch comprises a steel band 43 passing around a collar 44 fixed to the winding shaft 2. One end of the steel brake band 43 is attached to a pin 45 carried by a sheet metal clamp 46 which is fixed to the square portion of the sleeve 28 of the tilt member 7, 8, 9. When the shaft 2 is turned the friction or sliding coupling formed by the steel band 43 and the collar 44 transmits rotation by the intermediary of the clamp 46 and the sleeve 28 to the tilt member 7, 8, 9 and this latter may turn through a limited angle until its stop 30 abuts against one or the other of the abutments 31 or 32, on the bearing bracket 3. When the shaft 2 is further turned, the collar 44 slides relatively to the steel band. Also in this example, it is accordingly possible to tilt the slats, by operation of the tape used to lower or to lift the blind, in any position of the blind between fully lowered or fully raised position. Instead of using a steel band for the friction or sliding coupling, a stitf steel wire could be used. Lowering of the blind is obtained by turning the shaft 2 in the direction of the arrow b in Fig. 12. It is seen that in this direction of rotation, the friction of the sliding coupling tends to close the steel band 43 around the collar 44 and accordingly to exert a braking action on the shaft upon lowering of the blind. When raising the blind, the shaft 2 is turned in opposite direction; the movement of rotation tends to loosen the steel band 43 on the collar 44, and the coupling is subjected to minimum friction and accordingly offers a small resistance only against raising of the blind.

What I claim is:

A Venetian blind comprising a head support, a winding shaft extending longitudinally of said support, tilting members carried by said shaft for limited angular movement relative to the shaft, abutment means on said support coacting with the tilting members, slat carrying ladder tapes suspended from said tilting members, winding spools fixed to said shaft, a blind lifting element attached to each spool to be wound thereon for lifting the blind, driving means for turning said shaft in one or the other direction for raising and lowering the blind, a resilient forked member encircling said shaft, friction layers mounted in said forked member bearing upon said shaft, means for adjusting the amount of friction with which said friction layers bear upon said shaft and means interconnecting said forked member and a tilting member to cause movement of said tilting member with said shaft in either direction of rotation thereof until said tilting member engages said abutment means.

References Cited in the file of this patent UNITED STATES PATENTS 2,23l,778 Swanson Feb. 11, 1941 2,276,716 Cardona Mar. 17, 1942 2,579,144 Griesser Dec. 18, 1951 2,604,939 Griesser July 29, 1952 

